Excellent electrochemical properties of graphene-like carbon obtained from acid-treating natural black talc as Li-ion battery anode.

Abstract Because the commercialized graphitic carbon as an anode material is still limited by low capacities and poor long cyclic stability, new carbonaceous materials with good electrochemical performance are still needed to be sought. In the present work, a new fluorinated carbon material was obtained from natural black talc ore by HF acid-treating method. The influences of heat treatment on the composition, morphology and structure characteristics of the fluorinated carbon were investigated and possible fluorination/defluorination mechanisms were proposed. As an anode material for Li-ion battery, the electrochemical performance of the samples was greatly influenced by their surface characteristics. The fluorinated carbon showed high capacities of ∼756 mAh/g and ∼620 mAh/g at rate of 0.1 C and 0.2 C, which resulted from more active sites provided by plenty of fluoride groups on the surface of the fluorinated carbon. In contrast, the sample annealed at 800 °C exhibited relatively high capacity of ∼477 mAh/g at rate of 0.1 C with excellent rate performance due to its better electrical conductivity caused by the removal of the fluorine groups. The present work provides a new direction for the application of black talc and other similar natural minerals. Graphical abstract Image 1 Highlights • A new fluorinated carbon material was obtained from natural black talc ore. • The effect of heat treatment on the fluorinated carbon were investigated. • The electrochemical performances of these samples were studied as anode materials. • The fluorinated carbon annealed at 800 °C exhibited excellent rate performance. • The lithium storage mechanism of these samples were explored. [ABSTRACT FROM AUTHOR]